code: def strip_vl_extension(filename):
      """Strip the vega-lite extension (either vl.json or json) from filename"""
      for ext in [".vl.json", ".json"]:
          if filename.endswith(ext):
              return filename[: -len(ext)]
      else:
          return filename
  
file_path: pdvega/doc/sphinxext/pdvega_ext/utils.py
imports: import ast
  import json
  import importlib
  from hashlib import md5
  from itertools import tee, chain
label_desc: Use image node_id 4 for calling a global function with example usage: strip_vl_extension(filename) and returns: filename, filename